Can ACT 10 sync over Parallels 5 (via a VPN)?

I am currently running an iMac in one office and another iMac interstate.

These machines (including a PC) are all networked to access an external hard drive (Western Digital My Book World Edition) via VPN router (D-Link DI824VUP).

Each iMac is running Parallels 5 (with XP SP3), in order to run ACT 10. Both iMacs are running Snow Leopard.

I am desperately trying to find a way to synchronize my ACT databases via VPN but hit a roadblock with Parallels.

With an earlier version of ACT (version 6) we were able to synchronize each machine’s database to a database file which was located on our external hard drive. Same VPN router and iMacs. Each local ACT database simply needed to be pointed to the external hard drive (master) database file in order to sync and we ran into no problems whatsoever.

Now, ACT 10 doesn’t seem to allow this. I’m guessing this is due to the nature of Parallels set up, and how the new ACT 10 now syncs.

Again we have a database file located on each machine, but there seems to be no way to set up a master database on the external (which we could then sync with).

Furthermore, we cannot sync directly due to ACT 2010’s requirement that the database be stored on its local drive (eg C). Each local drive is not accessible via VPN (even though it has sharing enabled).

Desperately seeking advice pertaining directly to this scenario – we have considered other software but really would like to stick with ACT.